Pathetic service from ssda

I have had a Jetstores axoi t on 2012. The lady from ssda phoned me in 2016. She offered me a discount price of ?R4600. I had to pay it in three debit orders. She would then send me a paid up letter. This year I got calls from mba stating I have to pay R7600. I went into Edkon(edgars) where the lady helpes me phoning ssda. They agreed that the account is paid up. They will send me a letter,they promised. Even though they had two years to do that. After two phone calls after that,still nothing. I am really tired pleading with them to do their work. And in the meantime I still get phonecalls from mba. This is really pathetic. Give me my letter please.